The subject invention is generally directed to multilayer photopolymer holograms, and more particularly to a multilayer photopolymer hologram structure that is comprised of a plurality of photopolymer layers laminarly attached to each other without intervening adhesive layers.
In a number of applications such as laser eye protection and head-up displays, the desired holographic effect might not be capable of being optimally achieved with a single hologram, for example as a result of bandwidth requirements. In such applications, a plurality of hologram layers, each configured to provide a portion of the desired hologram effect, can be laminarly attached to each other. However, a consideration with known multilayer hologram structures is the use of adhesive layers, which adds to the thickness of the multilayer hologram structures and can result in distortion of the hologram layers as well as distortion of the composite holographic image produced thereby. The problems of distortion and blurring can be particularly critical for a deep hologram that produces an image relatively far way from the hologram plane.